1. Field of the Invention
The invention relates to a power management system and a power management method, and more particularly to a power management system and a power management method for performing power management on a management subject apparatus that includes a charging unit for charging a storage apparatus installed in a vehicle.
2. Description of the Related Art
In an electric automobile and a plug-in hybrid automobile, a storage battery is charged from a commercial power supply in a household or the like. Japanese Patent Application Publication No. 5-207668 (JP-A-5-207668) discloses a technique with which a secondary battery of an electric automobile or the like can be charged rapidly while leveling a load applied to an alternating current power supply side. Normally, a direct current power having a low current is obtained from an alternating current power supply by a rectifier and a charger and charged to a facility storage battery. When a charging request is issued from the electric automobile or the like, a direct current power having a large current is obtained from the storage battery by the charger and rapidly charged to a storage battery of the electric automobile or the like.
However, with the technique disclosed in JP-A-5-207668, a vehicle issues a charging request to a charging facility in order to set the charging facility in a charge mode. When a vehicle that is not capable of communicating this type of charging request appears, a load applied to the alternating current power supply side cannot be leveled, and therefore a charging capacity on the charging facility side must be increased.
Further, depending on the facility storage battery that levels the load, the size of the charging facility may increase, leading to an increase in cost.